Fluid mixing device



Oct. 29, 1957 E. P .AGHNlDEs 2,811,340

FLUID MIXING DEVICE Filed Dec. 29, 1949 Milli@ INVENTOKR zzzezff/zzde.;

ATTORNEY FLUID MIXING DEVICE Elie P. Agbni-des, NewYork, N. Application December-29, 1949, Serial No. 135,645 15 Claims. ftCi. 251-76) 'This invention relates to a device for intimately mixing .two or more ,iluids of which at least vone .of the fluids is under pressure. More particularly, although not exclu- .sively, the invention relates to devices .for mixing a liquid under pressure with atmospheric air.

One object of this invention is to `produce an .aerator `of the type shown and broadly claimed in my U. S. Patent 2,210,846, entitled Fluid Mixing Device, granted August 6, 1940, embodying features of adjustment which extend the usefulness of the device.

It is an important object of the invention to provide a device which .is adjustable to thereby .adapt .itself to different conditions, and which will mix, .at a given maximum available pressure, iluids of widely different viscosity.

Still another object of .the invention is .to provide a iluid mixing device with ,increased mixing `capacity when the necessary pressure power is available.

A further object of the invention is to vprovide Va water aerator for domestic use which can be adjusted to adapt 'itself to dilerent pressures and volumes `of ow, .this being desirable since pressures and volumes of ow vary from -home to home.

#t 4is another object of the invention to obtain a liquidkgas mixture, where the number of the gas bubbles in the Lstream and the size of the bubbles may be regulated as desired.

Still another object of the invention is to provide a device which is operable to selectively produce either a coherent mixture ofthe two uids or the dispersion of -one `of the 'uids in the form of divergent streams of mist or fdroplets.

Another object is to provide a uid mixing device that has awide range of application yet is low in cost, is simple v'in construction, is rugged, and is easy to operate.

iOther -objects and advantages of this invention will be readily apparent to those skilled in the art as this descripltion proceeds.

My invention includes a device intended to be con- 'nected to a source of uid (for example water) under pressure. The device has a chamber provided with one or more apertures through which the uid iiows to the chamber, and means for increasing the total open crosssectional area o'f -said aperture or apertures. Proper openings are provided leading into the chamber for one or more fluids l(for example air or other gases) which are either entrained into said chamber according to the well-known Venturi principle, `or reach said chamber under their own power. In the alternative they may travel to the chamber under the action of 'both forces. Means (for example one 'ormore screens) are provided in the path of the stream .of the first-named iluid after lit leaves said apertures for finely breaking up the rst-named fluid and offering sutlcient resistance for thoroughly mixing it with the other fluid for uids. An outlet for the .chamber is providedfrom which the mixed uids can emerge.

A feature of my invention is an arrangement of means 4in the `:path -of a uid emerging 'with substantial velocity from the aperture or apertures, the means being adapted l ce 2,811,340

'Patented Oct. 29, `1195.7

.-2 to mix intimately -theuids, and means to vary'the'frelation .between the said velocity and the said resistance. The range of the variation comprehends velocity-resistance -ratios at Vwhich the vdevice will discharge a bubbly stream when said device is applied to mixing .a gas with ,a liquid, .such for instance -as air with water.

In the preferred embodiment of my invention the means for var-ying the velocity-.resistance ratio is realized through .decrease or increase of the size of the aperture or apertures, lthereby decreasing, or rincreasing the velocity ofthe uid delivered into the aforesaid chamber, with or without .simultaneous `displacement .of the ,position of the screens .in the path of the -fluid emerging from the aperture or apertures.

The variation of the velocity-.resistance ratio can also Vbe obtained Yby lmerely increasing or decreasing the distance between .the :aperture or apertures, and the means in 4.the `path `of .the fluid, .but this system has the inconvenience vof .increasing the length Aof the device, if the variation to coveran appreciable range.

The velocity-resistance ratio can also .be varied if .the Iconstruction is such .that the uid emerging from the aper- .ture or apertures can be directed so as to strike different `types of means `offering variable resistance, -to produce diierent kinds of streams according to the type of .means impinged upon.

A highly efficient lmeans for intimatelymixing the fluids is .a fine wire mesh screen located between the apertures and discharge end ofthe. device. The use of screens is very convenient as they enable 4the designer to obtain .any .desired resistance by selecting the number of screens used and/or by using ner or coarser screens. The size of the mesh employed ris not critical, but I have obtained good results by using screens of 40 wires per inch of .00 "f wire diameter, or screens of 29 x 310 wires per Ainch o'f .0114 and .0102" respectively. When the device is used lin connection with water aeration, 'for instance, the use of such screens finely breaks up the waterV and offers su'ilicien't resistance for thoroughly mixing it with air. Onfthe other hand, the resistance of the screen is low .enough to ,permit the passage .of considerable volume of air in the 'form of bubbles disseminated in the water. The streamlets o'f aerated Water are sutl'lciently close together so that on issuing they join each .other to form a single stream.

In the drawings, Figure 1 is a part vertical section of one form of the invention. Figure 2 is a sectional view taken along line 2 2 of Figure 1. Figure 3 illustrates the device of Figure 1 after certain adjustments. Figure 4 illustrates different output streams emerging from the `device of Figure 1, each representing a different adjustment. Figures 5 through 9 inclusive each are part vertical sections of modified forms of the invention. Figures 8A and 8B illustrate the upper and lower diaphragms respectively of Figure 8, and Figures 9A and 9B illustrate the upper and lower diaphragms respectively of Figure '9.

Referring to Figure 1, the vertical section illustrates an internally threaded cap kadapted to beattached to -the faucet 101, however it is Aunderstood that any other form of faucet attac'zhing means `may be used. The cap 100 defines a vertical central hole 102 vin which is located a conical body 103 (shown Vpartly cross-sectioned). The body 103 includes a pluralityof lfour webs 104. The iirst fluid, which may be water, under pressure, emerges downward from faucet 101 *and jpast the conical body 103. Thesecond Huid, lwhich may be vatmospheric air, enters along .the inner wa'll of the lower cap 105 and through hole 106. The upper cap 100 has an exteriorly threaded rim 107 which .contains a plurality of inlet lholes 106. The -lower Ycap 1.05 carries means .108, which may bea screen, to finely breakup and mix the iluids. lower cap 105 may be rotated about the stationary threaded rim 107 and when so rotated moves with respect to the rim, it moving upward when rotated clockwise (as viewed from the discharge end) and downward when rotated counter-clockwise. When the lower cap 105 is rotated and moves downward, the conical body V103,V which depends mainly on screen 108 for vertical supporL-'mo'ves downward aided in such motion'by the pressure of the fluid. Figure 3 illustrates the position of thefparts under these circumstances. i l l f With the parts in the position shown in Figure l, the cross-sectional area of ow through hole102 is a minimum, hence for any given faucet pressure the velocity of ow is a maximum but the volume of flow is a minimum. In this position the following; results are obtained assuming that means 108 is a screen thatolers little'resistance to the passage of the uid and further assuming the liquid from the faucet is water under adequate pressure: The water leaving the outletend 109 is brokenup and emerges as a divergent stream of droplets as shown in Figure 1. However, when the body 103 is lowered by rotating cap 105 a small amount the velocity of the water entering chamber 110 decreases. As a result the screen offers suiicient resistance for thoroughly mixing the water and the air and thereafter uniting the aerated water to form a white coherent stream having air bubbles as shown in Figure 4a. The water thus drawn is crystal clear as the bubbles escape instantly from the water drawn. When the body 103 is further lowered by further rotation of cap 105 the body 103 will be pushed to a further downstream position by the water under pressure and the velocity of the water is further decreased. Figure 3 illustrates the position, now being discussed, of the several parts involved. Under these conditions the amount of air entrained is so little that when it is broken up it forms only minute particles in suspension in the water rendering the Stream grayish in color. The water thus drawn may be more or less cloudy but it clarifies itself slowly, and a stream of it in the form in which it emerges from outlet 109 is shown in Figure 4b. When cap 105 is further rotated to lower body 103 as much as possible the water entering chamber 110 will not have adequate velocity to entrain any air, and the resulting stream will be plain water as shown in Figure 4c. Y

While body 103 has four webs 104, this number may be increased or decreased in number, and if increased it is clear that the webs will form narrow grooves which respectively produce thin streamlets.

In the device of Figure 5 the webbed conicalbody 804 i depends on the screen for vertical support as in Figure l. In the position shown, the fluid under pressure enters the chamber 301 through the perforations 802. The latter are of proper size to give a ow into the chamber S01 of lluid under pressure having sufficient velocity to entrain the second fluid and to effect thorough mixing at lowest uid pressure. When greater pressure is available, and a greater volume of mixing is desired, then the casing S03 may be rotated counterclockwise `to allow the webbed conical body 804 to move downwardly under the pressure of the fluid and allow additional iiow of uid into the chamber through the space between the webs 805. The second fluid enters through openings 806.

In the device of Figure 6, there is a cup 901 having perforations 910 on the top and perforations 911 on the sides. This cup 901 supports perforated disc 902. At the position shown, the uid under pressure enters the chamber only through the holes 903. The cup is directly supported by screen 907, and has webs 909 around the top. Additional flow in the chamber, of fluid under pressure, is obtained by unscrewing the casing 904, to allow the cup 901 to go downwards under the pressure of the uid, and to permit the webbed conical top ofY said cup 901 to admit more uid into the chamber. The second uid enters duct 908. It is noted that when the device is in the position shown, the mixture will be discharged through the orice in discharge funnel 905 which is connected to the casing 904 by means of arms 906. Discharge funnel 905 is adapted to be physically detached from and removable from the arms 906. If this funnel is completely removed from the entire device, the discharge orifice is effectively enlarged. It is clear that this device has not only a variable orifice for the admission of the uid under pressure but it also has a discharge outlet end of variable size.

In the device of Figure 7 perforated discs 1301 and 1305 have fixed positions, but perforated discVZ is carried by square rod 1306 which is in turn supported by the screens in the lower rotatable cup 1307. In the position shown the device is set up for maximum flow through the perforated disc 1301. If the device is to be used in connection with domestic water, aeration disc 1301 has 40 to 50 hole s of 1 mm. diameter each. The number of holes for other purposes will depend on the pressure available, and on the viscosity of the fluids to be mixed. In case of domestic water I found that 40 holes of 1 mm. diameter will produce aeration in homes having a normal ow under as low water pressure as l5 to 20 pounds per square inch but the results improve as the pressure increases. In case narrow canalisations and low pressure will not permit the device to entrain a second fluid and/ or mix the two fluids, then the casing is partly unscrewed until the perforated disc 1302 comes into contact with disc 1301. Disc 1302 is provided with holes some of which are concentric and face the holes of disc 1301 has 40 to 50 holes of l mm. diameter each. The of disc 1301 are either smaller in diameter or fewer in number. I found that 20 holes of 0.8 mm. diameter is a satisfactory minimum. Disc 1302 is attached to a rod 1306 of square section which travels upwards when the casing is being rotated clockwise and downwards by gravitation and under the pressure of the uid upon the disc 1302 as the casing is unscrewed. It is clear that as the ldisc: 1302 gets closer to disc 1301 the flow through the latter decreases gradually, and at the point of contact of the two discs a minimum flow with the greatest stream velocity inside the chamber 1303 is obtained. The fluid perforated disc 1305 has a total open cross-sectional area bigger than that of disc 1301.

In the device of Figure 8, there are two superposed perforated discs 1401 and 1402, respectively illustrated in Figures 8A and 8B, disc 1402 being rotatable by operating the handle 1403. The discs have rows of holes of different size. Each disc has rows of large holes and rows of small holes. When large ow of fluid under pressure into chamber 1404 is desired, handle 1403 is rotated to obtain the facing of the larger holes in the two discs thus causing the facing of the smaller holes of the two discs. When less flow is desired the small holes of each disc rotate to partially cover the large holes of the other one. rPhe Huid strikes the plain part of perforated plate 1405 and due to its kinetic energy it is broken up and thoroughly mixed with the uid entering through the duct 1406. Below the plate is positioned a screen 1407. Figures SA and 8B show only one set of cooperating holes, it being understood that other similar groups of holes may be added in these discs.

In the device of Figure 9 the perforated discs 1601 and 1603 have rows of holes respectively as shown in Figures 9A and 9B. FPhe upstream perforated disc 1601 can be rotated by means of handle 1602 so as to have its holes permit three different positions; first the outer row of holes 1603 open. This gives a spray (like lan ordinary shower) if a screen is not placed in its path, and a diverging stream of droplets if a screen is placed in its path. In the second position the central holes 1605 would only be open so as to give a coherent mixture of uids discharging through the orifice 1606. In the third position, holes 1603 in the periphery and holesY 1605 in the center would be lopen so as to obtain two different kinds of streams simultaneously. Screens 1604 may be employed, land yar may enter through ducts 1607. Itis understood that Figures `9A and 9B showonly one cooperating -group of holes and that other similar groups maybe added.

While I have referred to screens, other Iforaminous means can Vbe used to effect .the mixing.

The several devices shown are made readily removable to lpermit 'cleaning iand replacement. In the construction of Figure 9, the superposed discs each have one large orifice which at a certain position faces the large orifice in the other `disc to permit the washing out-of big particles which may have accumulated .upstream said discs.

While I spoke of webbed .conical bodies, it is clear that conically grooved cylindrical bodies are their equivalents. Such a body may have one groove with an opening at the base equivalent to 1 mm. diameter, increasing gradually. Whether the body is acylinder with kgrooves gradually increasing in depths, or it is a webbed cone, or just a cone, is not important. The aperture or apertures at the base of the body may be very small, or even nil, since the gradually increasing opening or openings, will be obtained as the conical (or the webbed or the grooved) body is being lowered.

The perforated discs of Figures 5, 6, 7 and 9 could be convex or concave respectively when it is desired to obtain streamlets emerging into the chamebr in a divergent or convergent form.

I claim to have invented:

1. A device for producing la coherent jet of water containing air bubbles, comprising a chamber, the inlet end of which is adapted for connection with the discharge end of a tube containing water under pressure and the outlet end of which is adapted to discharge the said coherent jet, means for restricting the size of the upstream end of the chamber and having at least one orifice through which the stream of water is adapted to be forced into the chamber with substantial velocity, an air port opening into the chamber through which air is induced by the stream of water, means in the path of the stream of Water after it leaves the .orifice and before it discharges at the outlet end, for finely breaking up the water and for offering suflicient resistance for thoroughly mixing it with air, means for thereafter uniting the aerated water to form a coherent jet having small bubbles disseminated throughout the jet, manually movable means on the outside of said device, and means in the device and driven by said manually movable means for greatly enlarging the size of said orifice, to change the character of the stream of water leaving the device from said coherent bubbly jet to a lgrayish stream having minute vparticles of air therein.

2. A device for producing a coherent jet of water `containing air bubbles, comprising a chamber, the inlet end of which is adapted for connection with the discharge end of a tube containing water under pressure and the outlet end of which is adapted to discharge the said ccherent jet, means for restricting the size of the upstream end of the chamber having at least one orice through which the stream of water is adapted to be forced into the chamber with substantial velocity, an air port opening into the chamber through which air is induced by the stream of water, means, in the path of the stream of water after it leaves the orifice and before it discharges at the outlet end, for finely breaking up the water and for offering suflicient resistance for thoroughly mixing it With air and for thereafter uniting the aerated water to form a coherent jet having small bubbles disseminated throughout the jet, the resistance offered by the said lastnamed means and the cross sectional area of the orifice being proportioned to effect the entrainment Iand mixing of the air with water before their discharge from the said outlet end, and supporting means for said first-named means and said last-named means, said supporting mea-ns including manually operable means for moving said firstnamed means andthe last-named means Yrelatively 'closer together, to a sufficient extent to change the character of the stream leaving `the device.

3. A device .for producing a coherent iet of water containing air bubbles, comprising Ia chamber, the inlet end of which isadapted for connection with the discharge end AOf a tube Icontaining water under pressure and the outlet .end of which 'is .adapted to discharge the said :coherent jet, means .at ,the upstream end of the chamber having at least Vone orifice through which the stream of water is adapted ,to .be Yforced -into .the .chamber with substantial velocity,

.an .air Aport opening into .the chamber Vthrough which air fis induced by .the .stream ,of water, resistance means ,in the .path vof the stream .of water .after it leaves the .orifice and .before it-dischargesat the outlet end, .for vfinely breaking up .theV water .and for .offering sufficient resistance for thoroughly mixing it with .air and for -thereafter uniting the ,aerated .water to form a .coherent jet having -small bubbles disseminated .throughout the Ijet, .and means adjacent Ythe orifice for varying the discharge rate through `saidorifice over a wide `range to thereby change the `character of .the Tjet leaving the device, the resistance vmeans comprising a screen gat the discharge end of the Vchamber; the last-named means including a valve plunger Vmovable in and out `of said orifice, said plunger being mounted von said screen, said last-named means also 'including mea-ns for moving the screen toward and away Vfrom `the orifice.

4. A device -for producing a coherent `jet of water containing a-ir bubbles comprising first and second tubular Vconcentric pipes, the inside wall of one of which is contiguous `with the -outside wall ofthe other, said pipes being movable relative ,to each other in va direction Aparallel to their axes, one :ofsaid -pipes being a `fluid intake pipe adapted for connection toa source-of fluid and the -other pipe constituting an outlet pipe, flow restricting means attached to and located across the opening of the intake pipe, said flow restricting .means having an orifice therebular pipe `having internal threads engaging those at the edge of said flange, a conical plunger located insideof and substantially .concentric -with the inside wall of saidinlet pipe, said ,plunger having its small end considerably smaller than the .inside .diameter of said inlet pipe and having its larger endfacing downstream and being only .slightly smaller than the inside diameter of the inlet pipe,

.and a screen across the opening inthe outlet pipe near the downstream end thereof, the larger end of said Vplunger being mounted on said screen which acts as the primary supportfor the plunger whereby the plunger Amay be raised and lowered by rotation of the outlet pipe, said flange defining air ports therethrough.

6. A device for producing a coherent jet of water containing air bubbles, comprising a chamber, the inlet end cf which is adapted for .connection with the discharge end of a Atube containing water .under pressure and 1the outlet end of which is adapted to discharge the said coherent jet, means at the upstream end of the chamber having at least one orifice through which the stream 'of water is ,adapted to be forced into the chamber with substantial velocity, an air port opening into the chamber .through which air is induced by the stream of water, and a screen, in the path of the stream of water after it leaves the'orifice and before it discharges at the outlet end, for finely 'breaking up the water and .for offering sufficient resistance for thoroughly mixing it with air and for thereafter uniting the aerated water to form a coherent jet having small bubbles disseminated throughout the jet,

means mounting the screen for movement toward and away from said orifice, and a valve plunger mounted on said screen and extending into said orifice whereby movements of the screen will vary the flow through the oritice.

7. A device for producing a coherent iet of water containing air bubbles, comprising a chamber, the inlet end of which is adapted for connection with the discharge end of a tube containing water under pressure and the outlet end of which is adapted to discharge the said coherent jet, means at the upstream end of the chamber having at least one orifice through which the stream of water is adapted to be forced into the chamber with substantial velocity, an air port opening into the chamber through which air is induced by the stream of water, a screen in the path of the stream of water after it leaves the orifice and before it discharges at the outlet end, for finely breaking up the water and for offering sufficient resistance for thoroughly mixing it with air, and a tapered element having its smaller end in the orifice and its larger end extending downstream from the smaller end, said tapered element being mounted on said screen, and means mounting the screen for movement toward and away from said orifice.

8. A device for producing a coherent jet of water containing air bubbles, comprising a chamber, the inlet end of which is adapted for connection with the discharge end of a tube containing water under pressure and the outlet end of which is adapted to discharge the said coherent jet, valve means at the upstream end of the chamber having at least one orifice through which the stream of water is adapted to be forced into 'the chamber with substantial velocity, an air port opening into the chamber through which air is induced by the stream of water, means, in the path of the stream of water after it leaves the orifice and before it discharges at the outlet end, for finely breaking up the water and for offering sufficient resistance for thoroughly mixing it with air and for thereafter uniting the aerated water to form a coherent jet having small bubbles disseminated throughout the jet, the resistance offered by the said second-named means and the cross sectional area of the orifice being proportionedV to effect the entrainment and mixing of the air with water before their dischargefrom the said outlet end, said valve means including two parts one of which defines the orifice and the other of which varies the size of the orifice, and means outside of the device and outside the path of iiow for moving the second part to vary the size of the orifice.

9. The device defined in claim 7 having in addition webs radially mounted on the tapered element to break up the flow into distinct streams of water.

10. Adevice for producing a coherent jet of water containing air bubbles, comprising a chamber, the inlet end of which is adapted for connection with the discharge end of a tube containing water under pressure and the outlet end of which is adapted to discharge the said coherent jet, valve means at theV upstream end of the chamber having at least one orifice through which the stream of water is adapted to be forced into the chamber with substantial velocity, an air port opening into the chamber through which air is induced by the stream of water, means, in the path of the stream of water after it leaves the orifice and before it discharges at the outlet end, for finely breaking up the water and for offering suicient Vresistance for thoroughly mixing it with air and for thereafter uniting the aerated water to form a coherent jet having small bubbles disseminated throughout the jet, the

'resistance oered by the said second-named means and the cross sectional area of the orifice being proportioned toV effect the entrainment and mixing of the air with water 'before their discharge from the said outlet end, said valve means including certain orifices that are always open and direct flow toward one part of the resistance means and including at least one orifice directed at another part of the resistance means through which fluid flow is regulated, and a partition separating the streams emanating from the continuously Vopen orifices from all through which the flow is regulated.

11. The device defined in claim 10 in which said second-named means comprises a screen, means for moving the screen toward and away from the inlet end of the chamber, said partition resting on and being supported by said screen, said valve means being carried by said partition, said valve means including means for varying the volume of flow when moved toward or away from the inlet end of the chamber.

l2. A device for producing a coherent jet of water containing air bubbles comprising a chamber, the inlet end of which is adapted for connection with the discharge end of a tube containing water under pressure and the outlet end of which is adapted to discharge the said coherent jet, means at the upstream end of the chamber having at least one orifiice through which the stream of water is adapted to be forced into the chamber with substantial velocity, an air port opening into the chamber through which air is induced by the stream of water, means, in the path of the stream of water after it leaves the orifice and before it discharges at the outlet end, for finely breaking up the water and for offering sufficient Vresistance for thoroughly mixing it with air and for thereafter uniting the aerated water to form a coherent jet having small bubbles disseminated throughout the jet, the resistance offered by the said second-named means and the cross sectional area of the orifice being proportioned to effect the entrainment and mixing of the air with water before their discharge from the said outlet end, and an element partially blocking one of the fluid inlets into said chamber, and a manually movable part mounted outside the path of flow for controlling the position of said element to increase and decrease its blocking effect.

13. A device for producing a coherent jet of water containing air bubbles, comprising a chamber, the inlet end of which is adapted for connection with the discharge end of a tube containing water under pressure and the outlet end of which is adapted to discharge the said coherent jet, valve means at the upstream end of the chamber having at least one orice through which the stream of water is adapted to be forced into the chamber with substantial velocity, an air port opening into the chamber through which air is induced by the stream of water, means, in the path of the stream of water after it leaves the orifice and before it discharges at the outlet end, for finely breaking up the water and for oering sufficient resistance for thoroughly mixing it with air and for thereafter uniting the aerated water to form a coherent jet having small bubbles disseminated throughout the jet, the resistance offered by the said second-named means and the cross sectionai area of the orifice being proportioned to effect the entrainment and mixing of the air with water before their discharge from the rsaid `outlet end, and a removable funnel mounted in the outlet end of the device, said funnel having a smaller outlet than the outlet of the device.

14. A device for producing a coherent iet of Water containing air bubbles comprising a chamber the inlet end of which is adapted for connection to the discharge end of a tube containing water under pressure and the outlet end of which is adapted to discharge the said c0- herent jet, means at the upstream end of the chamber having at least one orifice through which the stream of water is adapted to be forced into the chamber with substantial velocity, an air port opening into the chamber through which air is induced by the stream of water, mixing means in the path of the stream after it leaves the orifice and before it discharges at the outlet end for finely breaking up the water and for offering sufficient resistance for thoroughly mixing it with air and for thereafter uniting the aerated water to form a coherent jet having small bubbles disseminated throughout the jet, means mounting the mixing means for movement toward and away from said oriflce, and a Valve member mounted on said mixing means and extending into said oritice whereby movements of said member will vary the ow through the on'iice.

15. A device for producing a coherent jet of a liquid containing air bubbles comprising a chamber the inlet end of which is adapted for connection with the discharge end of a source of liquid under pressure, means including a plurality of orices near the upstream end of the charnber for projecting a plurality of separate streamlets into the chamber with substantial velocity, an air port opening into the chamber through'which air is induced by the stream of liquid, mixing means in the path of the stream lets after they leave the orifices and before the liquid is discharged from the chamber for finely breaking up the liquid in the streamlets and for offering sucient resistance for thoroughly mixing it with air and for discharging the aerated liquid to form a coherent jet having small bubbles disseminated throughout the jet, and means manually operable from outside of the chamber for continuously varying the cross-sectional area of at least one of said orifices to a suicient extent as to vary the velocity and quantity of water directed upon the mixing means 10 from such a small velocity and high rate of flow that the liquid discharged is a plain non-aerated stream of water to such a large velocity and small volume that the aforesaid aerated stream is discharged.

References Cited in the le of this patent UNITED STATES PATENTS 355,250 Blass Dec. 28, 1886 773,350 Tinsley Oct. 25, 1904 1,110,453 Monosmith Sept. 15, 1914 2,086,711 Friedrich July 13, 1937 2,134,182 Goodrie Oct. 25,' 1938 2,210,846 Aghnides Aug. 6, 1940 2,316,832 Aghnides Apr. 20, 1943 2,388,508 Timpson Nov. 6, 1945 2,405,375 Smith Aug. 6, 1946 2,423,650 Hurst July 8, 1947 2,510,395 Goodrie June 6, 1950 2,564,060 Gettins Aug. 14, 1951 FOREIGN PATENTS 219,084 Switzerland Apr. 19, 1941 492,511 Belgium Dec. 2, 1949 1,000,443 France Oct. 10, 1951 

